您当前的位置:首页 > IT编程 > python
| C语言 | Java | VB | VC | python | Android | TensorFlow | C++ | oracle | 学术与代码 | cnn卷积神经网络 | gnn | 图像修复 | Keras | 数据集 | Neo4j | 自然语言处理 | 深度学习 | 医学CAD | 医学影像 | 超参数 | pointnet | pytorch | 异常检测 | Transformers | 情感分类 | 知识图谱 |

自学教程:Django实现翻页的示例代码

51自学网 2021-10-30 22:38:00
  python
这篇教程Django实现翻页的示例代码写得很实用,希望能帮到您。

Django提供了翻页器。用Django的Paginator类实现

一、views模块导入Paginator类实现数据分页

ApiTest/apiviews.py

每行都加了注释,希望有助于理解。

from django.shortcuts import renderfrom ApiTest.models import ApiTestfrom django.contrib.auth.decorators import login_requiredfrom django.core.paginator import Paginator, EmptyPage, PageNotAnInteger, InvalidPage@login_requireddef api_test_manage(request):    username = request.session.get('user', '')    # 获取所有接口测试数据    apitest_list = ApiTest.objects.all().order_by('id')    # 生成Paginator对象对数据分页,每页显示10条数据    paginator = Paginator(apitest_list,10)    # 使用request.GET.get()函数获取url中的page参数的数值。默认第1页    page = request.GET.get('page', 1)    # 把获取的当前页码数转换成整数类型    current_page = int(page)    try:     # 获取查询页数的接口数据列表,page()函数会判断page实参是否是有效数字。page()函数源码附在文章的最后        apitest_list = paginator.page(page)    except PageNotAnInteger:        apitest_list = paginator.page(1)    except (EmptyPage, InvalidPage):     # paginator.num_pages        apitest_list = paginator.page(paginator.num_pages)    return render(request, "apitest_manage.html", {'user': username, 'apitests': apitest_list})

二、将views的数据渲染到前端模板上

在对应的html文件中加入此段代码即可。

<div class="container">    <ul class="pagination" id="pager">        {# 上一页链接 #}        {% if apitests.has_previous %}        <li class="previous"><a href="/apitest_manage/?page={{ apitests.previous_page_number }}" rel="external nofollow" >上一页</a></li>        {% else %}        <li class="previous disabled"><a href="#" rel="external nofollow"  rel="external nofollow" >上一页</a></li>        {% endif %}        {# 中间数字显示 #}        {%  for num in apitests.paginator.page_range %}            {%  if num == currentPage %}                <li class="item active"><a href="/apitest_manage/?page={{ num }}" rel="external nofollow"  rel="external nofollow" >{{ num }}</a></li>            {% else %}                <li class="item"><a href="/apitest_manage/?page={{ num }}" rel="external nofollow"  rel="external nofollow" >{{ num }}</a></li>            {% endif %}        {% endfor %}        {# 下一页链接 #}        {% if apitests.has_next %}   {# 如果有下一页,则正常显示下一页链接 #}            <li class="next"><a href="/apitest_manage/?page={{ apitests.next_page_number }}" rel="external nofollow" >下一页</a></li>        {% else %}            <li class="next disabled"><a href="#" rel="external nofollow"  rel="external nofollow" >下一页</a></li>        {% endif %}    </ul></div>

三、效果展示

四、Paginator类源码

此类主要用在views文件

class Paginator:    def __init__(self, object_list, per_page, orphans=0,                 allow_empty_first_page=True):        self.object_list = object_list        self._check_object_list_is_ordered()        self.per_page = int(per_page)        self.orphans = int(orphans)        self.allow_empty_first_page = allow_empty_first_page    def validate_number(self, number):        """Validate the given 1-based page number."""        try:            if isinstance(number, float) and not number.is_integer():                raise ValueError            number = int(number)        except (TypeError, ValueError):            raise PageNotAnInteger(_('That page number is not an integer'))        if number < 1:            raise EmptyPage(_('That page number is less than 1'))        if number > self.num_pages:            if number == 1 and self.allow_empty_first_page:                pass            else:                raise EmptyPage(_('That page contains no results'))        return number    def get_page(self, number):        """        Return a valid page, even if the page argument isn't a number or isn't        in range.        """        try:            number = self.validate_number(number)        except PageNotAnInteger:            number = 1        except EmptyPage:            number = self.num_pages        return self.page(number)    def page(self, number):        """Return a Page object for the given 1-based page number."""        number = self.validate_number(number)        bottom = (number - 1) * self.per_page        top = bottom + self.per_page        if top + self.orphans >= self.count:            top = self.count        return self._get_page(self.object_list[bottom:top], number, self)    def _get_page(self, *args, **kwargs):        """        Return an instance of a single page.        This hook can be used by subclasses to use an alternative to the        standard :cls:`Page` object.        """        return Page(*args, **kwargs)    @cached_property    def count(self):        """Return the total number of objects, across all pages."""        c = getattr(self.object_list, 'count', None)        if callable(c) and not inspect.isbuiltin(c) and method_has_no_args(c):            return c()        return len(self.object_list)    @cached_property    def num_pages(self):        """Return the total number of pages."""        if self.count == 0 and not self.allow_empty_first_page:            return 0        hits = max(1, self.count - self.orphans)        return ceil(hits / self.per_page)    @property    def page_range(self):        """        Return a 1-based range of pages for iterating through within        a template for loop.        """        return range(1, self.num_pages + 1)    def _check_object_list_is_ordered(self):        """        Warn if self.object_list is unordered (typically a QuerySet).        """        ordered = getattr(self.object_list, 'ordered', None)        if ordered is not None and not ordered:            obj_list_repr = (                '{} {}'.format(self.object_list.model, self.object_list.__class__.__name__)                if hasattr(self.object_list, 'model')                else '{!r}'.format(self.object_list)            )            warnings.warn(                'Pagination may yield inconsistent results with an unordered '                'object_list: {}.'.format(obj_list_repr),                UnorderedObjectListWarning,                stacklevel=3            )

五、Page类源码

此类主要用在html文件

class Page(collections.abc.Sequence):    def __init__(self, object_list, number, paginator):        self.object_list = object_list        self.number = number        self.paginator = paginator    def __repr__(self):        return '<Page %s of %s>' % (self.number, self.paginator.num_pages)    def __len__(self):        return len(self.object_list)    def __getitem__(self, index):        if not isinstance(index, (int, slice)):            raise TypeError(                'Page indices must be integers or slices, not %s.'                % type(index).__name__            )        # The object_list is converted to a list so that if it was a QuerySet        # it won't be a database hit per __getitem__.        if not isinstance(self.object_list, list):            self.object_list = list(self.object_list)        return self.object_list[index]    def has_next(self):        return self.number < self.paginator.num_pages    def has_previous(self):        return self.number > 1    def has_other_pages(self):        return self.has_previous() or self.has_next()    def next_page_number(self):        return self.paginator.validate_number(self.number + 1)    def previous_page_number(self):        return self.paginator.validate_number(self.number - 1)    def start_index(self):        """        Return the 1-based index of the first object on this page,        relative to total objects in the paginator.        """        # Special case, return zero if no items.        if self.paginator.count == 0:            return 0        return (self.paginator.per_page * (self.number - 1)) + 1    def end_index(self):        """        Return the 1-based index of the last object on this page,        relative to total objects found (hits).        """        # Special case for the last page because there can be orphans.        if self.number == self.paginator.num_pages:            return self.paginator.count        return self.number * self.paginator.per_page

到此这篇关于Django实现翻页的示例代码的文章就介绍到这了,更多相关Django 翻页内容请搜索51zixue.net以前的文章或继续浏览下面的相关文章希望大家以后多多支持51zixue.net!


pytorch--之halfTensor的使用详解
一劳永逸彻底解决pip install慢的办法
万事OK自学网:51自学网_软件自学网_CAD自学网自学excel、自学PS、自学CAD、自学C语言、自学css3实例,是一个通过网络自主学习工作技能的自学平台,网友喜欢的软件自学网站。